University of Miami researchers looked at effects of COVID-19, not vaccines

A recent Instagram post points to research out of the University of Miami’s Miller School of Medicine as evidence that COVID-19 vaccines will affect sperm production. 

"The Miller School researchers have confirmed that the COVID19 virus can affect sperm production inside the testes," the post says. "What’s in the experimental ‘vaccine?’ They can’t deny it won’t affect the male sperm production either by injection or transmission."

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In November, the University of Miami announced that a new study by Miller School of Medicine researchers found that COVID-19 can invade the testicles in some men who are infected with the virus. 

The study was published in the World Journal of Men’s Health. Dr. Ranjith Ramasamy, the lead author and the director of reproductive urology at the Miller School, said at the time that "the findings could be the first step in discovering COVID-19’s potential impact on male fertility and whether the virus can be sexually transmitted," according to the university. 

By analyzing testis tissue from six men who died of COVID-19, the researchers found impaired sperm function in the tissue of three of the men, and evidence of COVID-19 in the tissue of a fourth man.

Other viruses, such as the mumps, are known to affect sperm production and fertility. However, according to the university, "more studies are needed to evaluate exactly how testis tissue responds to the virus and what that might mean to male fertility and sexual transmission."

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The study says that it is "limited by the small sample size and inability to assess the long-term consequences" of COVID-19 on sperm production. In its conclusions, the researchers wrote: "The findings of this study could be the first step in discovering impacts to fertility or the possibility of sexual transmission of the virus. On the basis of these preliminary findings, we believe that COVID-19 can penetrate the blood-testis barrier and enter the testis in some men."

The study does not mention vaccines. We reached out to Ramasamy to find out if the Instagram post accurately characterized their work. 

Dr. Daniel Nassau, one of Ramasamy’s fellows and an investigator on the study, responded. 

"I am not sure where they are getting vaccine from this article, but that statement is not true," he said. 

The school’s researchers are separately evaluating how mRNA vaccines may affect fertility, he said, and they’re waiting for the results to be published. But, he said, "we do not think the vaccine will affect male fertility."

A fever can temporarily suppress male fertility, Dr. Parviz Kavoussi, a reproductive urologist at St. David’s South Austin Medical Center, told the Austin American-Statesman. And a percentage of people who receive any vaccine, including a COVID-19 vaccine, could experience a fever after getting the shot. But the effects are short-term.

"At three months, it’s going to bounce back," he said. 

We rate claims that studies show the COVID-19 vaccine will affect sperm production False.